Difference between pathlib.Path().resolve() and pathlib.Path().parent

Question

I'm having a bit of a hard time understanding the difference between pathlib.Path().resolve() and pathlib.Path().parent.

If I want to be able to get the directory of the current script, do these serve the same purpose?

And are both of these location-agnostic, i.e. if I were to move the files to a different location, would my script still run?

Answer 1

The method pathlib.Path().resolve() will return an absolute path. If the path is already absolute the method will have no effect.

For example assuming you are in the working directory /home/python and run the following

In: pathlib.Path().resolve()
Out: "/home/python"

In: pathlib.Path(".").resolve()
Out: "/home/python"

In: pathlib.Path("foo/bar.txt").resolve()
Out: "/home/python/foo/bar.txt"

In: pathlib.Path("/home/python").resolve()
Out: "/home/python"

To explain the example above, if you instantiate a path class pathlib.Path() without any arguments it will use . as default value, which refers to the current working directory. So the first two examples both resolve to /home/python.

foo/bar.txt is a relative path. If your working directory is /home/python it will resolve to the absolute path /home/python/foo/bar.txt. If you are in the working directory /root it will resolve to /root/foo/bar.txt.

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pathlib.Path().parent is another path object representing the parent of the path given.

# In working directory /root
In: pathlib.Path("/home/python").parent
Out: PosixPath("/home")

In: pathlib.Path("/home/python").parent.resolve()
Out: "/home"

# In working directory /home/python
In: pathlib.Path("foo").parent
Out: PosixPath(".")

In: pathlib.Path("foo").parent.resolve()
Out: "/home/python"

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Yes your script will still run in other directories if you watch out for certain things.

# /home/python/foo.py

print(pathlib.Path().resolve())

Running this script from the directory /home/python will result in a path like this /home/python.

If you run the script from /home like this python/foo.py it will result in a path like this /home

If you watch out for potholes like this you should be fine to run your script from any directory. Doing mistakes here usually results in file not found errors.